1. Field of the Invention
The present invention relates to an information updating device, an information distributing device and an information processing system that perform processing related to update of feature information about a feature, and to a method thereof, a program thereof and a storage medium storing the program.
2. Description of Related Art
There has been conventionally known a navigation system that acquires a map or information about various facilities from a server via a network to update map or information stored in a terminal unit such as an in-vehicle or mobile navigation device and a mobile phone (see, for instance, Reference: JP2004-20220A, pages 15 to 24).
In the navigation system disclosed in the Reference, a communication navigation terminal unit transmits to a communications center device an update request for requesting transmission of map data (e.g., map data including information about various facilities positioned on a road map or a map) with a predetermined period having passed from the latest update request date and time. Then, if the communications center device recognizes that the requested map data has been upgraded at least partially, the map data is transmitted to the communication navigation terminal unit. The communication navigation terminal unit then updates the map data.
In an arrangement of the Reference described above, even in a case where, for instance, only one of all feature information respectively about a plurality of features positioned on the map in the map data has been upgraded, the entire map data including feature information that has not been upgraded might be transmitted and received. Thus, the arrangement includes a problem, where the feature information that has not been upgraded and thus does not require to be updated is also transmitted and received, so that amount of various information to be transmitted and received becomes large.